The first and at one time largest of the microstock libraries. Now (perhaps unfortunately?) part of the Getty images empire. Since 2003 we have watched the cost of photos steadily rise, gone are the days when you could ge a good usable image for $1, they introduced XSmall images and in effect the cost of an image tripled overnight.

Overall the site is very popular among buyers, if difficult to get images accepted; you should include iStockPhoto in your portfolio, just don't lose any sleep if you make less on this site than on some of the other smaller sites. Following a change to their best match algorithm in early 2009 I have seen good returns throughout this year (2009). This might also be partially due to getty cannibalising traffic/adspace/sales that were previously covered by Stockxpert, Stockxchange and other ex Jupiter Sites.

• The Killer Search

From what I can see istockphoto has pretty much the best search technology I have ever seen when it comes to a buyer finding images. It makes it slightly more difficult to upload to as you have clarify the meaning of your keywords. for example include a keyword 'orange' and you will be asked to tick one of two boxes Orange (Descriptive Colour) or Orange (Citrus Fruit), or perhaps you include the keyword 'lead' the response will be Lead (Metal), Dog Lead (Pet Equipment), Leading (Moving Activity), Graphite (Material) etc and the list goes on for 1000's of different ambiguous words in the English language. This really is cool stuff, as an image purchaser trying to clarify exactly what sort of image you want using words is a difficult business and this helps significantly.

• Exclusive Photographer?

A big decision for any photographer to make. Becoming exclusive with istock will mean that you cannot upload images to any other site. I can't comment on what its like to be exclusive as i have no experience, many people swear by it. exclusive photographers get a larger percentage per image purchase, and also receive 'care' from the site - istock will chase people who use your images in breach of the license on your behalf.

The top exclusive photographers also get to sell their images via getty's image network (including photodisk) increasing sales potential dramatically.

• Audio, Video, Ilustration

Along with several other agencies istockphoto also accept video and vector illustrations. They have recently launched their new audio library 'istockaudio'. Even if you only contribute photographs to istock it's important to consider that buyers may find istock a convenient one-stop-shop for all their media needs, and these buyers will be your potential customers.

It's true that at present many buyers are only in the market for images, but demand for video is growing fast and commission rates are higher. I can see one recipe for success in this emerging market is having quality video with matching print resolution images, hence designers can create matching online video and web/print campaigns; perhaps even just the option to go back and download matching images if they become needed will be enough to make your video work stand out.

Conclusion

Despite my criticisms of this site, the low commission level (although fotolia recently dropped their basic commission to 25%), restrictions on the number of images that can be submitted (for full time microstockers istock is quite restrictive) the fact that it has fallen from the #1 spot, tedious keywording process etc, I still recommend istockphoto as one of the top four earning microstock agencies. The microstock market moves and changes all the time, a brief look at istock right now (Dec 09) shows them to be my top earner despite worse results from 2008 where they were trailing around 3rd.

Visit istockphoto